Enterprise Network Ops Dashboard

Infrastructure Network Topologies

Global production network topologies and segment systems.

HQ Datacenter

[ Replace with Core Topology Image ]

Spine-Leaf Core Fabric

Interconnecting physical ISE Cubes, DNA Spaces Controllers, and Edge routing aggregations.

Unified Comms Node

[ Replace with CUCM Cluster Topology Image ]

CUCM High Availability Cluster

Subscriber/Publisher database sync layouts routing cross SIP Trunk access paths.

Systems Engineering Learning Hub

Select an enterprise architecture platform to view deployment specifications.

Standard Runbooks & Operational SOPs

Tiered runtime workflows for infrastructure maintenance.

Server Triage & Incident Resolution

Common structural error codes, debug vectors, and how to fix them.

ISE Error Matrix

RADIUS Drop

Symptom: 11007 Process Failure (RADIUS Request Dropped)

Root Cause: Shared secret mismatch between NAS device and ISE policy engine, or network transit dropped responses.

Fix: Re-verify exact CLI key layout parameters on NAD client nodes; inspect active system logging streams via `show logging application prrt-server.log`.

DNAC Sync Fault

Inventory Fail

Symptom: Device Inventory Sync Stuck Loop / Timeout Error

Root Cause: Overdue SSH key exchanges, or access-list filters are blocking traffic on port `tcp/22` or `tcp/830` (NETCONF).

Fix: Confirm end-to-end routing visibility on access filters; force manual device telemetry sync tasks using the inventory control module.

CUCM Registry Drop

SIP 503

Symptom: SIP Endpoint Drops with Error 503 (Service Unavailable)

Root Cause: Call Manager service engine limits reached, or transactional call routing rules point to offline trunks.

Fix: Access Cisco Unified Serviceability dashboard panels; confirm CallManager core service daemon loops show active operational state metrics.

WLC Capwap Break

DTLS Down

Symptom: Access Points Stuck in AP Join Loop Sequence

Root Cause: MTU size issues along the path, or invalid AP certificate expiration parameters matching corporate trust chains.

Fix: Adjust path definitions with `capwap ap mtu 1400`; bypass strict MIC/SSC certificate constraints inside global parameters if testing aged nodes.

Transactional Packet Flows & Sequence Models

Tracing directional signaling mechanics inside secure enterprise networks.

802.1X Dot1x Authentication Sequence Flow

01

Supplicant (Client PC) → Authenticator (Switch Port)

Physical linkup triggers transmission of EAPOL-Start frames to the local access layer port.

02

Authenticator → Supplicant

The access switch sends back an EAP-Request/Identity frame, asking for the client's credentials.

03

Authenticator → Authentication Server (Cisco ISE Core)

The switch encapsulates the received EAP-Response payload into standard UDP RADIUS Access-Request packets sent toward port 1812.

04

Cisco ISE Evaluation Engine Evaluation

Matches incoming parameters against Identity Stores and Authorization Rules, returning a RADIUS Access-Accept containing download-ready ACLs (dACL) or VLAN assignment parameters.

Access Violation Policy Denied